Disk array controllers are a technology for managing disk drives and presenting the disk drives as logical units to a computer system. A Redundant Array of Independent Disks (RAID) controller is a disk array controller for a RAID array. RAID controllers often include disk cache to reduce access times to the RAID array. Storage technologies have progressed so that it is logical to provide multiple tiers of cache in RAID controllers. RAID controllers may now include an extended cache in addition to the primary cache. The primary cache typically has faster access times and has a lower capacity than the extended cache.